Automatic burglar-alarm and door-bell



UNITED STATES GEORGE FRANK KIERSON AND ALFRED K. YOUNG, OE ALLEGHENY, PENNSYLVANIA.

AUTOMATIC BURGLAR-ALARM AND DOOR-BELL.

SPECIFICATION forming part of Letters Patent No. 448,051,6lated March 10, 1891.

Application filed July 1, 1890. $erial No. 357,416. (No model.)

To all whom, it may concern.-

Be it known that we, GEORGE FRANK KIER- SON and ALFRED K. YOUNG, of Allegheny, in the county of Allegheny and State of Pennsylvania, have invented a new and useful Improvement in Automatic Burglar-Alarms and Door-Bells, which improvement is fully set forth in the following specification and accompanying drawings, in which Figure I is a sectional side elevation of a vestibule or doorway equipped with our improved automatic burglar-alarm and doorbell; Fig.1l, a detail View of the platform and its connections, and Fig. III a detail view of the clock-work which operates the alarm-bell.

Our invention relates to improvements in burglar and door alarms; and its object is to provide a simple and reliable device especially designed to guard against the depredations of hall and sneak thieves and at the same time to fulfill all of the requiremen s of a doorbell.

A doorway furnished with this device cannot be entered, even if the door be wide open, without giving forth an alarm, as if by magic.

The invention consists in detaching a suitable portion of the floor of a vestibule and arranging it as a platform, the outer edge of which has a limited vertical movement on a series of levers so combined as to prolong and transmit the movement through suitable clock-work to an alarm bell or gong, which gives warning whenever the doorway is entered.

It will be understood that the device is equally adapted to dwellings which have no vestibule. A section of the threshold may be used for the platform.

Referring to the accompanying drawings, A designates a platform composed of a section of the floor of a vestibule. Bars B and B are attached to the platform, and their inner ends may be pivoted to the joists beneath the floor. A block C is attached to the under side and near the front of the platform, which, on being pressed down, engages the multiplying-levers D and E, situated below and connected and arranged as shown. lVhen the platform is depressed, the movement is extended and transmitted by the cord or chain F, attached to the front end of the lever E, and, being guided by the pulleys, extends to the vertical rod G, and thence 'through the bell-crank lever H and coupling-rod I to the lever J, having a pawl K, which engages a ratchet-wheel L, attached to the inner side of the master-wheel M. The movement is transmitted and prolonged through the intermediate spur-wheel N and the escape-wheel O to the anchor-escapement P, provided with a clapper Q, which vibrates rapidly on the gong R. \Vhen pressure is removed from the platform A, the multiplying-levers D and E are returned to their normal position by means of the spring 6, and the platform is again level. If desired, the platform may be rendered inoperative by a button S, and under the front edge of the platform, which may be I readily turned by a knob T. 'When the platform is thus stopped, the gong may be rung in the usual manner by a crank U, which depresses the lever E by means of the connecting-rod V.

The advantages of this device are obvious. It will be understood that a downward movement of the platform so slight as to be imperceptible is extended by the multiplying-levers and suffices to produce an alarm which is only more startling because its origin is so entirely mysterious. The floor of the vestibule being carpeted or otherwise covered, there is no visible means by which so surprising a result could be produced.

lVhat we claim as new is- 1. The combination of the platform A, hinged and movable 011 suitable supports and having on the under side the block 0, combined with the multiplying levers D and E, situate beneath and moved by the downward pressure of said platform, and the rope or chain F, connected to the front end of the le ver E, and the rod, crank, lever, and gong, all operated as and for the purposes described.

2. In combination with the platform A and multiplying-levers D and E, situate beneath and operated by said platform, and the chain F, connected to Said lever E, and the rod, wehavehereunto ourhz nds, this 11th day crank, and lever attachments, as described, of June, 1890, in the presence of witnesses. [o the button S under the front edge of the plat- Y ,T form, movable by handle T, whereby the platg% g 5 form may, when desired, be kept in a fixed J horizontal position, so that the ordinary door- \Nitnesses'. gong may be rung.

EDWARD J. DONNELLY, H. I. RILEY.

In testimony that We claim the foregoing 

